ACOUSTIC LOCATION OF GUNSHOTS USING COMBINED ANGLE OF ARRIVAL AND TIME OF ARRIVAL MEASUREMENTS

A gunshot location system computes candidate gunshot locations [ 314] from angle-of-arrival information [ 304, 308] and time-of-arrival information [ 312] provided by acoustic sensors [ 300, 302] . In addition to an angle, each sensor calculates an angular uncertainty [ 306, 310] from impulses received at four or more microphones having rotational symmetry. An intersection of one or more time-of-arrival hyperbolas with one or more angle-of-arrival beams [ 322] is used to determine a candidate gunshot location. In simple environments, a location can be confirmed with just two sensors allowing sensor density to be significantly reduced, while in complex environments including reflections, blocking, and interfering acoustic events, the additional angle-of-arrival information improves location accuracy and confidence, allowing elimination of candidate locations inconsistent with the combined time-of-arrival and angle-of-arrival information.